The invention is directed to the mobile collection, processing and disposal of waste liquids containing oily components, solids, and other contaminants. It is particularly useful for, but by no means limited to, the clean up of oily, watery waste liquid from washing operations and the like.
In one of the known systems for handling waste liquids from washing operations, a wash pad, typically of concrete, is constructed over a large (e.g., 1000 gallon) surge tank equipped with an oil/grease trap. Waste water, collected by the wash pad, is drained into the surge tank, where there is an opportunity for solids to settle and the oily fractions to float to the top. After a sufficient waiting period, the collected waste liquid is pumped out and directed to a separating system, where the oily materials can be removed and the processed water reused or discharged. This system, while functionally satisfactory, requires that machinery to be cleaned be transported to the cleaning area. It is not feasible for situations requiring the cleaning equipment to be brought to the site of the machinery.
Where cleaning is to be done at the site of the machinery, without benefit of a pre-existing wash pad, mobile clean up equipment is required, in order to avoid hazardous or contaminating spills into the ground and/or sewer systems, or into local streams and rivers. Typically, such spills are tightly regulated, and violations can bring costly and serious penalties.
Conventional mobile clean up systems typically involve a large capacity tank truck, capable of vacuuming up the entire quantity of waste liquid and transporting the liquid back to a stationary treatment plant for processing and disposal in a regulated manner. This approach has serious shortcomings, however. Among these is that the entire body of waste liquid is removed and transported off site, which can constitute the processor as both a generator and a transporter of waste liquid with permanent responsibility for the hazardous waste. Another shortcoming is that the mobile equipment typically has to be quite large, with a capacity of several thousand gallons, which is much larger than the typical volume of waste liquid required to be processed. This results in significant capital cost, as well as additional costs of maintaining a large and costly piece of equipment.
In accordance with the present invention, a novel and improved mobile recovery and processing system is provided, which is small and relatively inexpensive, which can be transported to the clean up site by a small, lightweight trailer or other vehicle, and which not only collects but also processes the waste liquid on site. Any materials classified as hazardous can be containerized and retained at the site at which they are generated, which greatly simplifies compliance with the various regulations relating to such materials and, correspondingly, reduces the costs involved in the clean up operations.
In a particularly preferred form of the invention, a portable processing system is comprised of four vessels, which may comprise ordinary, commercially available, open-topped steel drums. Three of the vessels are connected in series and typically activated by a vacuum source connected to the last vessel of the series. When the vacuum pump is activated, waste liquid is drawn into the first vessel, where it is settled and strained to eliminate solid materials, such as trash, dirt and the like. The waste liquid, substantially free of its solids content, then flows to the second vessel, which forms a significant part of the system and serves in a novel and efficient manner to separate oily constituents from the waste water. Processed water, substantially free of oily constituents, then flows from the second vessel into the third receptacle, where it is collected for re-use or disposal by the available sanitary system.
Pursuant to the invention, the second vessel or separator vessel incorporates first and second fluid chambers, advantageously in the form of a housing divided by a vertical wall. The housing can be mounted atop a drum-like receptacle into which the dividing wall projects. Oily waste water enters the first fluid chamber, where the oily components are retained, and processed water exits from the second chamber. The two chambers are in communication in their upper and lower portions, and an outlet for the second chamber establishes a normal liquid level for both chambers, located below the level of the upper communication but well above the level of the lower communication. Oily waste water enters the first chamber near the top and is baffled and caused to flow gently into a body of collected liquid. While in the first chamber, oil separates from the water, with the water ultimately flowing downward, under the dividing wall and then upward into the second fluid chamber. Periodically, when a sufficient layer of oily material has collected in the upper portion of the first chamber, it is drawn off and accumulated in a fourth, oil-receiving vessel. The separated oily materials can then be reprocessed in a suitable manner.
The system of the invention, while capable of being constructed of readily available, largely standardized and inexpensive components, it is adaptable to highly automatic operation, so that minimum operator attendance and attention is required.
Although the system of the invention is ideally adapted for trailer-mounted mobile utilization, it is sufficiently economical to be attractive as a fixed processing installation, as well where oily/watery waste materials are regularly experienced.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed disclosure of preferred embodiments and to the accompanying drawings.